Zeolite A

Zeolite A has replaced the phosphates in household detergents. Phosphates can cause eutrophication of lakes and rivers by stimulating the growth of algė and upsetting the natural balance.

Phosphates and zeolites act as water softeners. »Hard« water contains calcium salts which greatly reduce the surfactant effect of soaps and detergents.

Zeolite A is a aluminiosilicate. The crystal lattice carries a negative charge which is balanced by positive sodium ions (cations) in the interstices. The cations are loosely bound and can easily be replaced by other cations such as calcium. This is the principle of ion exchange.

Zeolites thus remove the calcium from solution. As far as is known they have no negative effect on the environment, unlike phosphates.